My girls have scratched up every piece of vegetation in their fenced area. I live in a city and have a small back yard. The girls are at the bottom of the yard and have an area about the size of a house trailer to roam in. I give them scrap veggies and the occasional cabbage on a bungee cord (highly entertaining). They are fed daily and there is usually extra feed left in the pan when I go to put more out. Is there something I can do to keep them busy during the day so some of the vegetation can grow back or is the bare yard just standard fare for chickens?